I would like to try to get into my laptop only via the internet without installing anything on my laptop.
Remote control.
Do you want to 'hack' your laptop? Then have fun…
If you just want to access it without installing anything, you can do so via VPN access to your local network and the pre-installed Windows remote desktop
Doesn't just work that way. You assume that there's no router. Is just something else than support via VPN and remote deskop etc to do.
You have to come through your router first.